• Journal of the Korean Society of Marine Environment & Safety
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• v.15 no.4
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• pp.297-313
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• 2009

Long-term trends and distribution patterns of water quality were investigated in the Gunsan coastal areas of Yellow Sea, Korea from 1972 to 2006. Water samples were collected at 6 stations and physicochemical parameters were analyzed including water temperature, salinity, suspended solids(SS), chemical oxygen demand(COD), dissolved oxygen(DO) and nutrients. Spatial distribution patterns of temperature, DO and SS were not clear among stations but the seasonal variations were distinct except COD and SS. The trend analysis by principal component analysis(PCA) during 24 years revealed the significant variations in water quality in the study area. Spatial water qualities were clearly classified into 3 clusters by PCA; station cluster 1, 2~4, and 5~6. Annual water qualities were clearly classified into 4 surface water clusters and 5 bottom water clusters by PCA. By this multi-variate analysis. The annual trends were summarized as follows; Salinity, pH and DO tended to increase since late 1970's, COD to increase since 1987, and SS to decrease and nutrients to increase in Gunsan coastal waters due to the input of fresh water from land same as in Kyoungin coastal area, Asan coastal area and Choensoo bay.

• Journal of Korea Water Resources Association
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• v.39 no.8 s.169
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• pp.637-644
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• 2006

In this study, the analysis of river naturalness and water quality were executed in the major rivers of the Nakdong River Basin. As a result, the assessment index of the General Evaluation was 1.428 to 4.107 as $1^{st}$ to $4^{th}$ grades. The River Shape was 1.929 to 4.429 as $2^{nd}$ to $4^{th}$ grades and the River Environment was 1.774 to 3.643 as $1^{st}$ to $4^{th}$ grades. As well, evaluation of water quality showed that concentration of pH was 7.102 to 8.497 mg/l, BOD was 0.748 to 5.271 mg/l, DO was 5.077 to 12.335 mg/l and 55 was 3.658 to 19.960 mg/l. The correlation between river naturalness and water quality was analyzed to investigate similarity and independence of river naturalness evaluation index. It was shown that coefficient of correlation was low with value of -0.1503 to -0.5886, therefore, was evaluated as independent.

• Journal of Life Science
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• v.14 no.3
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• pp.478-483
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• 2004

In a model reaction using lysyl oxidase purified partilally from bovine aorta, effect of L-ascorbic acid AsA on the oxidative reaction of lysine in collagen was investigated. Addition of Ash to the reaction mixture under aerobic conditions resulted in the decrease of enzymatic activity. In order to examine the specificity of AsA in the oxidative reaction of lysine, other reductants including A derivatives instead of AsA were added to the reaction mixture. Thiol such as glutathione had no effect on the activities of lysyl oxidase. on the other hand, it was observed that erythorbic acid, which was a stereoisomer of AsA, had the same inhibitory effect on this oxidative reaction as AsA. Moreover, by the addition of 3,4-dihydroxybenzoate, which was structural analog of AsA, the activities decreased in a similar manner to that of AsA. These results indicate that the regulatory effect of AsA on lysyl oxidase is attributed to characteristics of the structure. From the determination of Ash remained in the reaction mixture, it is shown that AsA concentration remarkably decreased by lysyl oxidase of the reaction mixture. It is hypothesized that endiol groups reduces the enzyme-bound $Cu^{+2}$ required for further progress of the reaction, and suggests that AsA regulates specifically the reduction of $Cu^{+2}$ required to oxidize lysyl oxidase. This findings support that AsA has an important regulatory role on the oxidative reaction of lysine and on changes of collagen cross-links with aging.

• Korean Journal of Plant Tissue Culture
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• v.24 no.2
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• pp.119-124
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• 1997

Plantlets were regenerated from various explants (shoot tip, leaf blade, petiole and root segments) via organogenesis and/or somatic embryogenesis from Armoracia rusticana(Lam) Gaerth., Mey, et Scherb.. Shoot regeneration rate from callus was highest on the MS mediums supplemented with 0.5 ㎎/L IAA, 5.0㎎/L BA and 10.0㎎/L spermine. A Low frequency of regeneration occurred on hormone-free MS medium. Multiple shooks were regenerated at a pH of 4.0 to 8.0 on MS medium supplemented with 1.0 ㎎/L BA and 0.1 ㎎/L NAA. Polyamines promoted shoot- and root-formation by 2 to 4 times normal, Specific proteins associated with organogenesis were identified. Somatic embryogenesis occurred directly from the leaf blade, petiole and root segments cultured on MS medium with 2.0 ㎎/L BA and 2.0 ㎎/L BA and 2.0 ㎎/L NAA. Three types of regeneration in A, rusticana were clearly established, which could be applied to the study of morphogenesis and genetics at cell, tissue and organ levels.

• Proceedings of the Korea Water Resources Association Conference
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• 2006.05a
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• pp.386-390
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• 2006

In this study, the analysis of river naturalness and water quality were executed in the major rivers of the Nakdong River Basin. As a result, the assessment index of the General Evaluation was 1.428 to 4.107 as $1^{st}\;to\;4^{th}$ grades. The River Shape was 2.111 to 4.048 as $2^{nd}\;to\;4^{th}$ grades and the River Environment was 1.774 to 3.238 as $1^{st}\;to\;4^{th}$ grades. As well, evaluation of water quality showed that concentration of hydrogen ion was 7.102 to $8.49mg/{\ell}$, BOD was 0.748 to $5.271mg/{\ell}$, DO was 3.668 to $19.960mg/{\ell}$ and SS was $5.077mg/{\ell}$. The correlation between river naturalness and water quality was analyzed to investigate similarity and independence of river naturalness evaluation index. It was shown that coefficient of correlation was low with value of -0.1503 to -0.5886, therefore, was evaluated as independent.

• Journal of the Korean Society for Marine Environment & Energy
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• v.14 no.3
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• pp.205-211
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• 2011

On board comparison of pH and total alkalinity measurement in seawater was carried out during the JES expedition on R/V Roger Revelle in the East Sea using 550 real seawater samples from the surface to the bottom. Spectrophotometry and potentiometry without liquid junction were compared for pH measurement. The pH values of two methods are generally in a good agreement. Spectrophotometry with a pipette provides higher value compare with the potentiometry in the deep layer, where pH values are lower. However, spectrophotometry without a pipette shows same values with potentiometry within their precision range. The pipetting procedure may remove of $CO_2$ in the sample, which causes increase of pH. Potentiometric titration methods using a closed-cell and an open-cell were compared for the total alkalinity measurement. Values from open cell method are smaller by about 5~10 ${\mu}mol\;kg^{-1}$ than those from closed cell method. This may be caused by the bubble formed in the closed cell during the experiment. Although any analytical method compared in this study for the pH or TA measurement can be applied, special attentions should be paid for satisfactory results.

• Journal of the Korean Society for Marine Environment & Energy
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• v.14 no.1
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• pp.1-10
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• 2011

To understand characteristics of the water quality on the coastal boundary on tidal flat, field observations between 2008 and 2009 were undertaken twice a month at five coastal areas (Muan bay, Tando bay, Hampyeong bay, Shinan Jido and Yeongkwang coastal areas). Yearly water temperature difference was large with the range between $1.3^{\circ}C$ and $31.1^{\circ}C$. Salinity was about 32 but was the lower less than 20 for the heavy rainfall season. DO was high in winter and low in summer according to the variation of water temperature. pH represented the variation similar to DO. Suspended solid was averagely high over 100 mg/l in Yeongkwang coastal area, especially. COD did not revealed large variation with the value of about 1 mg/l. DIN and DIP concentration were high when freshwater was highly input in summer. DIN concentration was low for winter and early spring but DIP concentration did not show the seasonal variation with the continuous increase from July 2009 to December 2009. Chlorophyll a appeared high for spring with approximately $10\;{\mu}g/l$ and was higher for summer in Yeongkwang coastal area than other sites. The results of principal component analysis conducted to compare the characteristics of water quality observed in study areas showed the distinguishable features as follows. The freshwater input fluctuation appeared as the first factor in Muan and Tando bays, and the change of water temperature was the first factor in Shinan Jido and Yeongkwang coastal areas. The influence mixed with the variation of freshwater outflow and the change of water temperature in Hampyeong bay was to be the first factor.

• The Korean Journal of Physiology
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• v.24 no.1
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• pp.161-170
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• 1990

The effects of $H^{+}$ on the arterial contraction and their mechanisms were investigated in the renal artery of a rabbit. The helical strips of isolated renal artery were immersed in the HEPES-buffered or $CO_{2}/HCO_{3}^{-}$-buffered Tyrode's solution. The contractions induced by agonists (norepinephrine, histamine, serotonin and angiotensin II) or high $K^{+}$ were observed with change of extracellular or intracellular $H^{+}$ concentration. The contractions induced by norepinephrine, histamine, serotonin, angiotensin II or high $K^{+}$ in HEPES-buffered Tyrode's solution were inhibited by increase in extracellular $H^{+}$ concentration and potentiated by decrease in extracellular $H^{+}$ concentration. The degrees of these effects were most evident in the contraction induced by serotonin and angiotensin II, moderate in those by histamine and high $K^{+}$, and least in those by norepinephrine. Maximal contraction by norepinephrine, histamine and high $K^{+}$ were not influenced by change in extracellular $H^{+}$ concentration, but influenced in those contration by serotonin and angiotensin II. The attenuated contractions by an acidic pH were not returned to the level of contraction at normal pH (7.4) by elevation of extracellular $Ca{2+}$ concentration. The agonists (norepinephrine, histamine and serotonin)-induced contractions in $Ca{2+}$-free Tyrode's solution were also attenuated by increase in extracellular $H^{+}$ concentration and potentiated by decrease in extracellular $H^{+}$ concentration. Elevation of $Pco_{2}$ in the $CO_{2}/HCO_{3}^{-}$-buffered Tyrode's solution, which increase the intracellular $H^{+}$ concentration, at constant extracellular pH (7.4), increased the contraction by 30 mM $K^{+}$. From the above results, it is suggested that the decrease in contractions by increase in extracellular $H^{+}$ concentration may be resulted from that $H^{+}$ make the receptors less sensitive to agonists and cell membrane hyperpolarize and then inhibit the $Ca{2+}$ influx as well as $Ca{2+}$ release from intracellular $Ca{2+}$ storage site.

• Korean Journal of Microbiology
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• v.30 no.6
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• pp.533-538
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• 1992

The generation time of Methylobacterium extorquens AMI growing on methanol at pH 5.5 and 7.0 was found to be 23 hand 8.3 h. respectively. The bacterium grown at pH 7.0 were found to contain more amounts of spermidine and putrescine than the cell grown at pH 5.5. Cells grown at both conditions exhibited strong methanol dehydrogenase (MDH) activity at the mid-exponential growth phase. The amounts of MDH. however. were found to be almost equal through all gro~1h phases. Cells growing at the stationary phase contained large amounts of cytochrome c. The cytochrome c content was higher in cells growing at pH 7.0 than the cells growing at pH 5.5. Cells growing at pH 5.5 in the presence of putrescine or spermidine contained increased amounts of putrescine. The level of spermine, however. was decreased and that of spermidine was not changed. Spermine added into the medium was found to have no effect on the level of cellular polyamines. Putrescine or spermidine added into the medium stimulated MDH and hydroxypyruvate reductase activities. but did not affect the contents of MDH and cytochrome c. It was found that preincubation of cell-free extracts with polyamines does not stimulate MDH and hydroxypyruvate reductase activities.

• Journal of dental hygiene science
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• v.10 no.2
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• pp.101-107
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• 2010

The purpose of this study was to analysis know the important oral environmental factors which affect halitosis components of the adult in order to provide basic data for halitosis prevention and establish a device to eliminate halitosis efficiently. The 97 adults who visited at the Dental Clinic in Metropolis (M=68, F=30) participated in this study that performed from March in 2009 to in 2010. The obtained results through items as caries status, periodontal status, salivary flow, the viscosity, pH, Snyder test, plaque deposit, tongue plaque and halitosis check were as followings. The average shame of halitosis components appeared at hydrogen sulfide 36.71 ppb methyl mercaptan 31.46ppb dimethyl sulfide 54.33 ppb and Ammonia 22.60 ppm. The normality and the detection comparative result dimethyl sulfide above reverse appeared highly at 46.9%, ammonia appeared highly at 52%. According to the Hydrogen sulfide level was a high relationship among age, CPI, tongue coat status, DMFT index which were statistically significant (p<0.05). According to the quantity of hydrogen sulfide level there was relationship where tongue coat status Saliva flow rate considers statistically(p<0.05). The quantity of methyl mercaptan level there was relationship where Dimethyl sulfide level, tongue coat status, Saliva flow rate considers statistically(p<0.05). The quantity of Dimethyl sulfide level there was relationship where Hydrogen sulfide level, ammonia level, tongue coat status, Saliva pH and Saliva flow rate considers statistically(p<0.05). Ammonia level there was relationship where Methyl mercaptan level, CPI, and Saliva flow rate considers statistically(p<0.05).